MLookup not returning results

[jomili]

I'm wanting to include the MLookup function in my addin, so I can let others use it, but I'm having trouble with the usability of the function itself. I have one workbook example where I use MLookup, though the function isn't in the workbook, instead it's in my Addin. That all works great.

So, now I'm trying it in a real world situation, and it's not working. See the example attached (I've moved my MLookup function to the workbook). I'm trying to return all Job Codes (column T) associated with the subject Posn Func Code (column A) by looking in Column S, and I'm getting VALUE errors. I'd appreciate it if anyone can point out what I'm doing wrong.

BTW, in this case I can use Rick Rothsteins LOOKUPCONCAT function, but I really want to get the MLookup working right for my team. I'd appreciate any help I can get.

Thanks,
John